I replaced my SC tensioner assembly last night, and put my oversized 3.5" idler back on the new one as I had before. Because of the added tension (the old one was weak), I have alot less clearance between the belt faces on that idler and the water pump now.

Today, I'm modifying my torque-axis mount to allow for my underdrive (10% larger) water pump pulley. I think I'm going to have to step down that tensioner idler pulley diamter to a 3.25" or 3.0" now.

FYI, on the Series 1 L67, the SC belt also drives the WP and the AC. Alt and PS are on the outer belt.

I had to deal with the same thing when I put on my underdrive water pump pulley. Then had to deal with the same thing again when I decided to bypass the A/C. After all of that I'm running a 2" tensioner pulley.

I had to ditch the 3.5" as I suspected. And even with the 3" stock diameter on the tensioner, it'* quite close to the WP pulley now. Not sure which direction I'm headed here.

I'll watch it for a bit, but I may end up having to go to a shorter belt to get that tensioner to ride higher. If I can do that, I'd like to go back to at LEAST a 3.25" idler pulley to get my beltwrap back on that 2.2" SC pulley.